As Earth's population is now over seven billion people and increasing rapidly, more food and natural resources are needed. Use of fertilizer and manure (or pesticides) would help increase crop yield and thus the amount of food. Fertilizer consumption depends on factors such as the choice of crops or forest plants, varieties and qualities of seeds, geography, rainfall, irrigation patterns, soil quality, farming methods, and sprayer and tillage technology and information. Although this disclosure is not limited to nutrients or even nitrogenous fertilizers, solutions or gases such as ammonia are familiar to most people with its pungent odor when the concentration of ammonia is high enough (over 50 ppm in air). Ammonia can be used in a reaction with carbon dioxide to produce urea. Ammonia nitrate can be produced through the combination of ammonia and nitric acid. Other fertilizer types produced on the base of ammonia include calcium ammonium nitrate (ammonium nitrate mixed with ground dolomite) and NP/NPK compound fertilizers.
In an agricultural setting, the liquid or semi-liquid (gas) state of these fertilizers or nutrients may be sprayed close to the soil or applied directly into the soil by an applicator mechanism. A sharp ground-engaging tool such as a shank or disk first cuts through the ground and creates a furrow into which the compounds are subsequently deposited. Compounds like liquid anhydrous ammonia (NH3) with a low boiling temperature point evaporate quickly and their fumes may linger in the air. There may also be tank leakages of ammonia compounds. Beginning at levels between 25-50 ppm, the fumes may cause some irritation. An end-user may not know when the gas in the atmosphere becomes a problem. Farmers also operate in a noisy environment that includes much vibrational motion (e.g. the tractor moving across uneven soil) where the compounds may be spread somewhat unevenly or in unpredicted parts of the soil.